The Methods Core provides expertise, leadership and infrastructure to promote and facilitate the quality of HIV research projects conducted by CHIPTS researchers and collaborators. The Core supports implementation of web and mobile phone technologies, provides statistical expertise, improves capacity for methods research, and supports evaluation studies by community partners. The Specific Aims are: 1. Science: Fostering cutting edge research by developing and applying innovative technologies and analytic strategies (e.g., modern measurement tools and techniques) to HIV research; 2. Networking: Connecting scientists across disciplines to understand the available analytic methodologies and linking scientists to partners with complementary expertise; 3. Capacity Building: Recruiting, mentoring, and retaining high caliber investigators with methods expertise and disseminating conventional and innovative methods, tools, and platforms. Comprehensive methods expertise is needed to provide the highest quality support to HIV researchers. The Methods Core is a backbone for CHIPTS research projects, playing an integral role on each project from initiation to completion. The Methods Core has identified different types of methods support needed by researchers and community partners, each differing in their resources and abilities. The Methods Core has developed a four-level system. Its structure, functions and strategies are based on the four levels of support outlined in Table 4.1. Table 4.1.: Methods Core Primary Functions 1. Innovative technology and methods 2. Advanced/conventional statistics 3. Assessment tools and strategies 4. Basic infrastructure: Information technology, data security, & data transfer Level 1: Innovative Technology and Methods. Mobile technologies and social media have transformed Americans' daily lives; in addition, they frequently offer lower cost options for implementing research in developing countries. For example, mobile phone data collection is often cheaper than traditional interviewing techniques in Africa. Research studies and assessments need to adopt strategies that are responsive to the changing environment. These new technologies offer opportunities to reach marginalized groups (e.g., drug using networks on Facebook) and ethnic minority persons. Prior to implementation, the social contexts, benefits and limitations of these new technologies need to be understood. For example, internet-enabled mobile phones may be practical for web-based data collection in the U.S., but scaled-down studies that rely on text messaging may be more suitable in developing countries. By staying on the cutting edge of technology, the Methods Core will offer the research community these new platforms and tools to maximize the opportunity to reach the populations they serve. Level 2: Advanced/Conventional Statistics. The Methods Core continues to develop and promote sophisticated analytic strategies and methods to create cutting edge designs to respond to the HIV pandemic. Many projects involving CHIPTS investigators, especially large multisite trials, require conventional and innovative statistical methods that advance the field. Advanced methods will especially be called upon with changing technologies, e.g. social network analysis for studies based on social-networking websites and time series analyses to handle real-time mobile phone behavioral assessment. Level 3: Assessment Tools and Strategies. The Methods Core offers consultation to CHIPTS investigators and research partners on assessment and measurement issues, instrument selection, and data collection strategies. The Core developed and maintains an assessment instrument bank, a central repository for numerous measures and scales (e.g., HIV risk behavior, mental health, quality of life, etc.) with assessments in multiple languages. In addition, the Methods Core will lead in the development of real-time and biomarker measurement strategies. For example, we will develop composite environmental stress measures, i.e. allostatic load, from individual stress biomarkers such as C-Reactive Protein and Epstein-Barr virus antibodies, and in turn, develop methods to combine self-reported and allostatic load measures to gain additional insight into health behavior and risk. Level 4: Basic Infrastructure: Information Technology, Data Security, and Data Transfer. The Methods Core will continue to serve as a key research infrastructure resource to investigators and research partners by providing assistance on information technology, data security, and cross-site data transfer. The Core will establish and maintain the necessary protocols to ensure the safety of research data, particularly data collected as part of multi-site projects. To provide these services, we can call upon a multidisciplinary team that includes statisticians, sociologists, computer scientists, engineers, data managers, neuroscientists, epidemiologists, and marketers.